Abstract: This invention relates to a method and a device for the processing of silver halide photographic materials. The method of the invention includes accurately measuring the concentration of a developing agent in a photographic developing solution to monitor the activity of the bath and/or the need to replenish it. This measurement is carried out using spectrophotometric means.

Abstract: A device for automatically measuring a concentration of a developing agent in a developing bath includes a voltage generator capable of generating at least one voltage ramp provided to feed a three-electrode cell; a potentiostat provided to maintain a constant potential difference between two electrodes; a peak detector provided to identify the maximum current flowing in the three-electrode cell that corresponds to the developing agent concentration; and a display unit provided to show the maximum current.

Abstract: The invention concerns a method for controlling the activity of a development composition which comprises, as a developing agent, an organometallic complex. The method includes measuring the variations in optical density difference of the composition that varies with the degree of oxidation of the organometallic complex. The method also makes it possible to regenerate the development composition by means of an electrolysis current. A device for controlling the activity of the development composition includes two light-emitting diodes of different wavelengths, the light beams of which pass through the development composition, and photodiodes to receive transmitted light.

Abstract: This invention relates to a 3-part kit preparing for a photographic developing bath for the processing of color photographic materials. The kit of this invention affords an efficient ready-to-use developing solution.

Abstract: Silver halide emulsions are disclosed containing silver halide grains capable of forming an internal latent image. Incorporated in the emulsions is a diphenylmethane nucleating agent, thereby permitting a direct-positive image to be formed on imagewise exposure and photographic processing.

Abstract: Silver halide emulsions are disclosed containing silver halide grains capable of forming an internal latent image. Incorporated in the emulsions as a nucleating agent is a dihydrospiropyran bis-condensation product of salicylic aldehyde and at least one heterocyclic ammonium salt, thereby permitting a direct-positive image to be formed on imagewise exposure and photographic processing.

Abstract: Silver halide emulsions are disclosed containing silver halide grains capable of forming an internal latent image. Incorporated in the emulsions as a nucleating agent is a heterocyclic compound having an arylaminovinylene or aryloxyvinylene substituent, thereby permitting a direct-positive image to be formed on imagewise exposure and photographic processing.